RESUMO
Antagonism of the gonadotropin releasing hormone (GnRH) receptor has resulted in positive clinical results in reproductive tissue disorders such as endometriosis and prostate cancer. Following the recent discovery of orally active GnRH antagonists based on a 4-piperazinylbenzimidazole template, we sought to investigate the properties of heterocyclic isosteres of the benzimidazole template. We report here the synthesis and biological activity of eight novel scaffolds, including imidazopyridines, benzothiazoles and benzoxazoles. The 2-(4-tert-butylphenyl)-8-(piperazin-1-yl)imidazo[1,2-a]pyridine ring system was shown to have nanomolar binding potency at the human and rat GnRH receptors as well as functional antagonism in vitro. Additional structure-activity relationships within this series are reported along with a pharmacokinetic comparison to the benzimidazole-based lead molecule.
Assuntos
Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/farmacologia , Piperazinas/síntese química , Piperazinas/farmacologia , Receptores LHRH/antagonistas & inibidores , Animais , Disponibilidade Biológica , Células Cultivadas , Meia-Vida , Compostos Heterocíclicos/farmacocinética , Humanos , Masculino , Piperazinas/farmacocinética , Ratos , Ratos Sprague-DawleyRESUMO
Pyrrole[2,3-d]azepines have been identified as potent agonists of the farnesoid X receptor (FXR). Based on the planar X-ray crystal structure of WAY-362450 1 in the ligand binding domain and molecular modeling studies, non-planar reduced compounds were designed which led to agonists that exhibit high aqueous solubility and retain moderate in vitro potency.
Assuntos
Azepinas/farmacologia , Pirróis/farmacologia , Receptores Citoplasmáticos e Nucleares/agonistas , Receptores Citoplasmáticos e Nucleares/metabolismo , Azepinas/química , Humanos , Modelos Moleculares , Ligação Proteica , Pirróis/química , Receptores Citoplasmáticos e Nucleares/química , Relação Estrutura-AtividadeRESUMO
A previous report described the serum LH suppression pharmacology of the 2-phenyl-4-piperazinyl-benzimidazole N-ethyluracil GnRH receptor antagonist 1 following oral administration in rats. A series of small heterocycles were appended to the 2-(4-tert-butylphenyl)-4-piperazinyl-benzimidazole template in place of the N-ethyluracil. Two imidazole analogues, 32 and 41, were shown to possess substantial in vitro potency at the target receptor (hGnRH IC(50) = 7 and 18 nM, respectively) and aqueous solubility (55 and 100 microg/mL at pH 7.4, respectively). Both compounds had high oral bioavailability in rats and 32 was further examined in an orchidectomized rat model for serum LH suppression based on increased volume of distribution over 41. Serum LH levels trended lower in orchidectomized rats following oral administration of 32.
Assuntos
Benzimidazóis/farmacologia , Piperazinas/farmacologia , Receptores LHRH/antagonistas & inibidores , Administração Oral , Animais , Benzimidazóis/química , Benzimidazóis/farmacocinética , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/química , Hormônio Luteinizante/sangue , Modelos Animais , Piperazinas/química , Piperazinas/farmacocinética , Ratos , Receptores LHRH/metabolismo , Relação Estrutura-Atividade , Fatores de TempoRESUMO
Using a cell-based assay, we have identified a new series of Notch-sparing gamma-secretase inhibitors from HTS screening leads 2a and 2e. Lead optimization studies led to the discovery of analog 8e with improved gamma-secretase inhibitory potency and Notch-sparing selectivity.
Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Química Farmacêutica/métodos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Receptores Notch/metabolismo , Doença de Alzheimer/tratamento farmacológico , Amiloide/química , Secretases da Proteína Precursora do Amiloide/química , Carbono/química , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Humanos , Modelos Químicos , Receptores Notch/antagonistas & inibidores , Relação Estrutura-AtividadeRESUMO
Antagonism of the gonadotropin releasing hormone (GnRH) receptor has shown positive clinical results in numerous reproductive tissue disorders such as endometriosis, prostate cancer and others. Traditional therapy has been limited to peptide agonists and antagonists. Recently, small molecule GnRH antagonists have emerged as potentially new treatments. This article describes the discovery of 2-phenyl-4-piperazinylbenzimidazoles as small molecule GnRH antagonists with nanomolar potency in in vitro binding and functional assays, excellent bioavailability (rat %F>70) and demonstrated oral activity in a rat model having shown significant serum leuteinizing hormone (LH) suppression.
Assuntos
Benzimidazóis/administração & dosagem , Benzimidazóis/química , Piperazinas/química , Receptores LHRH/antagonistas & inibidores , Administração Oral , Animais , Benzimidazóis/síntese química , Reagentes de Ligações Cruzadas/química , Glicolatos/química , Humanos , Hormônio Luteinizante/sangue , Masculino , Metilação , Estrutura Molecular , Piperazina , Ratos , Ratos Sprague-Dawley , Receptores LHRH/metabolismo , Relação Estrutura-AtividadeRESUMO
Trityl ethers were prepared in solution in a matter of minutes by treating trityl chloride with silver triflate in the presence of alcohols. Yields were comparable or better than known literature methods. The method was compatible with the base-labile Fmoc protecting group of amino alcohols and adapted for trityl protection of halo-containing alcohols. These base- and nucleophile-sensitive intermediates were anchored on trityl resin and further functionalized, displaying the utility of this approach for future combinatorial applications.
RESUMO
A solid phase tri-orthogonal protection/cleavage strategy that uses acidic, basic, and neutral conditions is described. Strategically protected alpha-azido-gamma-9-fluorenylmethyl-L-glutamate (1) and alpha-azido-epsilon-N-Fmoc-L-lysine (2) were incorporated into growing peptides on Wang resin using a novel azide protection strategy. These residues, separated by 1-3 monomers, were deprotected at the side chains and cyclized via lactam formation. The N-terminus was further functionalized to extend the chain. This method represents a straightforward protocol for peptide cyclization on solid support.
Assuntos
Peptídeos Cíclicos/síntese química , Peptídeos/química , Aminoácidos , Sítios de Ligação , Catálise , Reagentes de Ligações Cruzadas , Ciclização , Conformação ProteicaRESUMO
In an effort to develop orally active farnesoid X receptor (FXR) agonists, a series of tetrahydroazepinoindoles with appended solubilizing amine functionalities were synthesized. The crystal structure of the previously disclosed FXR agonist, 1 (FXR-450), aided in the design of compounds with tethered solubilizing functionalities designed to reach the solvent cavity around the hFXR receptor. These compounds were soluble in 0.5% methylcellulose/2% Tween-80 in water (MC/T) for oral administration. In vitro and in vivo optimization led to the identification of 14dd and 14cc, which in a dose-dependent fashion regulated low density lipoprotein cholesterol (LDLc) in low density lipoprotein receptor knockout (LDLR(-/-)) mice. Compound 14cc was dosed in female rhesus monkeys for 4 weeks at 60 mg/kg daily in MC/T vehicle. After 7 days, triglyceride (TG) levels and very low density lipoprotein cholesterol (VLDLc) levels were significantly decreased and LDLc was decreased 63%. These data are the first to demonstrate the dramatic lowering of serum LDLc levels by a FXR agonist in primates and supports the potential utility of 14cc in treating dyslipidemia in humans beyond just TG lowering.
Assuntos
Azepinas/síntese química , Hipolipemiantes/síntese química , Indóis/síntese química , Receptores Citoplasmáticos e Nucleares/agonistas , Animais , Azepinas/farmacocinética , Azepinas/farmacologia , Disponibilidade Biológica , Linhagem Celular , LDL-Colesterol/sangue , Feminino , Humanos , Hipolipemiantes/farmacocinética , Hipolipemiantes/farmacologia , Indóis/farmacocinética , Indóis/farmacologia , Macaca mulatta , Masculino , Camundongos , Camundongos Knockout , Microssomos Hepáticos/metabolismo , Modelos Moleculares , Ratos , Ratos Sprague-Dawley , Receptores de LDL/genética , Solubilidade , Relação Estrutura-Atividade , Triglicerídeos/sangueRESUMO
An efficient and mild method to couple aryl bromides and activated non-allylic alcohols in a Heck reaction with tandem isomerization to selectively afford high yields of 1,5-diarylalkan-1-ones has been developed. Mechanistic insight was gained through NMR studies of products derived from deuterium-labeled intermediates.
Assuntos
Álcoois Benzílicos/química , Brometos/química , Paládio/química , Catálise , Espectroscopia de Ressonância Magnética , Estrutura Molecular , EstereoisomerismoRESUMO
A potent, highly insoluble, GnRH antagonist with a 2-phenyl-4-piperazinylbenzimidazole template and a quinoxaline-2,3-dione pharmacophore was modified to maintain GnRH antagonist activity and improve in vitro pharmaceutical properties. Structural changes to the quinoxaline-2,3-dione portion of the molecule resulted in several structures with improved properties and culminated in the discovery of 6-([4-[2-(4-tert-butylphenyl)-1H-benzimidazol-4-yl]piperazin-1-yl] methyl)quinoxaline (WAY-207024). The compound was shown to have excellent pharmacokinetic parameters and lowered rat plasma LH levels after oral administration.
Assuntos
Benzimidazóis/síntese química , Quinoxalinas/síntese química , Receptores LHRH/antagonistas & inibidores , Administração Oral , Animais , Benzimidazóis/química , Benzimidazóis/farmacologia , Ligação Competitiva , Disponibilidade Biológica , Meia-Vida , Humanos , Técnicas In Vitro , Hormônio Luteinizante/sangue , Masculino , Microssomos Hepáticos/metabolismo , Orquiectomia , Hipófise/efeitos dos fármacos , Hipófise/metabolismo , Quinoxalinas/química , Quinoxalinas/farmacologia , Ensaio Radioligante , Ratos , Relação Estrutura-AtividadeRESUMO
A high-throughput screening campaign to discover small molecule leads for the treatment of bone disorders concluded with the discovery of a compound with a 2-aminopyrimidine template that targeted the Wnt beta-catenin cellular messaging system. Hit-to-lead in vitro optimization for target activity and molecular properties led to the discovery of (1-(4-(naphthalen-2-yl)pyrimidin-2-yl)piperidin-4-yl)methanamine (5, WAY-262611). Compound 5 has excellent pharmacokinetic properties and showed a dose dependent increase in the trabecular bone formation rate in ovariectomized rats following oral administration.
Assuntos
Osteogênese/efeitos dos fármacos , Piperidinas/farmacologia , Pirimidinas/farmacologia , Proteínas Wnt/agonistas , beta Catenina/agonistas , Animais , Domínio Catalítico , Linhagem Celular Tumoral , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Quinase 3 da Glicogênio Sintase/química , Glicogênio Sintase Quinase 3 beta , Humanos , Camundongos , Modelos Moleculares , Piperidinas/administração & dosagem , Piperidinas/farmacocinética , Pirimidinas/administração & dosagem , Pirimidinas/farmacocinética , Ratos , Transdução de Sinais/efeitos dos fármacos , Proteínas Wnt/metabolismo , beta Catenina/metabolismoRESUMO
The extracellular signal-regulated kinases 1 and 2 (ERKs 1/2) are known to participate in regulating transcription in response to moderate depolarization, such as synaptic stimulation, but how the same active enzyme can differentially regulate distinct transcriptional programs induced with abnormal depolarization (high potassium) is unknown. We hypothesized that ERK1 or 2 accomplishes this differential nuclear response through close association with other proteins in stable complexes. In support of this hypothesis, we have found that immunoreactivity for an apparent high molecular weight complex containing phospho-ERK1 increased in response to synaptic stimulation, but decreased in response to high potassium; p-ERK immunoreactivity at 44/42 kDa increased in both cases. Evidence supporting the conclusion that the band of interest contained ERK1 in a complex, as opposed to it being an unrelated protein crossreacting with antibodies against p-ERK, is that ERK1 (p44 MAPK) and 14-3-3 protein were electroeluted from the 160-kDa band cut from a gel. We also found the nuclear complexes to be exceptionally durable, suggesting a role for the crosslinking enzyme, transglutaminase, in its stabilization. In addition, we found other components of the ERK pathway, including MEK, ERK2, p90RSK, and Elk-1, migrating at higher-than-expected weights in brain nuclei. These results describe a novel stable complex of ERK1 in neuronal nuclei that responds differentially to synaptic and depolarizing stimulation, and thus may be capable of mediating gene transcription in a way distinct from the monomeric protein.